The purpose of this study is to perform ground-based research to study what happens to the
heart muscle in space. People who have problems with their aortic valve have an increase in
the amount of muscle in the left ventricle of the heart. After valve surgery, the amount of
muscle should decrease and return to normal. Astronauts lose heart muscle mass during space
flight. Our study will look at these changes in your heart, which we believe are similar to
what happens during long term space travel.
This study will look at the accuracy of three dimensional ultrasound imaging (echo) in
monitoring the changes in heart size and function following aortic valve replacement. We are
studying ways to prevent health-related problems that men and women will face on
long-duration space missions.
The hypothesis is that serial two dimensional and three dimensional echo will show accurate
changes in the left ventricle mass and volume following aortic valve replacement for aortic
stenosis or regurgitation
Diagnostic Three Dimensional Echocardiography Study Protocol
A. Aims The overall purpose of this study is to perform ground-based research, development,
and validation aimed at optimizing diagnostic ultrasound in manned spaceflight, with the
following unifying hypothesis: Serial 3D ultrasound examinations will enhance diagnostic
capabilities in manned spaceflight.
1. To optimize acquisition methods for 3D sonography using reconstruction and real-time
2. To determine the utility of serial 3D ultrasound examinations in identifying renal
calculi and their complications including the development and resolution of
hydronephrosis and calyceal dilatation.
3. To determine the utility of serial 2D and 3D ultrasound examinations in demonstrating
cardiac remodeling (changes in cardiac dimensions, volume, mass and function) and
defining its determinants after left ventricular unloading following aortic valve
replacement for aortic stenosis or regurgitation.
4. To determine whether changes in plasma BNP levels accurately reflect changes in LV mass
1. Serial 3D ultrasound examinations will allow accurate diagnosis of nephrolithiasis and
tracking of complications including hydronephrosis and calyceal dilatation
2. Serial 2D and 3D ultrasound will allow accurate tracking of changes in LV mass and
volume following aortic valve replacement (AVR) for aortic stenosis or regurgitation.
3. Changes in plasma BNP levels will fall in proportion to the decrease in LV mass and
- Scheduled for surgery for aortic stenosis or aortic regurgitation
- Previous open heart surgery